Linked Life Data

12227477

Source:http://linkedlifedata.com/resource/pubmed/id/12227477

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2002-9-13
pubmed:abstractText
This study was undertaken to determine the possible mechanisms of actions of monensin and digoxin by using isolated guinea-pig ventricular myocytes. Since Ca2+ is the major signal for triggering contraction of cardiac muscle, the objective of this study was to determine whether monensin and digoxin affect the [Ca2+]i of cardiac myocytes and if so is this effect due to an increase in [Na+]i. Three different concentrations of digoxin (0.3, 1 and 3 micromol/l) and three different concentrations of monensin (0.3, 1 and 3 micromol/l) were used. Each treatment was monitored for two hours by using computerized fluoroscopy. Both digoxin and monensin increased the [Ca2+]i and accelerated the onset time of [Ca2+]i increase in a dose-dependent manner. Normal myocytes (loaded with fura-2 for 30 min before the treatment) were also compared with 'weakened' myocytes (loaded with fura-2 for 3 h before the treatment to create a 'weakened' condition). It was found that although 0.3 micromol/l monensin and digoxin did not change the [Ca2+]i in normal myocytes, they increased the [Ca2 +]i in 'weakened' myocytes. Finally, a Na+-free medium was used to demonstrate the effect of [Na+]o on both monensin- and digoxin-induced increases in [Ca2+]i. It was found that digoxin did not increase the [Ca2+]i in the Na+-free medium. Although monensin increased the [Ca2+]i in the Na+-free solution, this increase was not as large as in the Na+-containing medium. The results of the study led to the conclusion that the positive inotropic effect of digoxin depends on [Na+]o. However, monensin increases [Ca2+]i in Na+-dependent and -independent ways. An addition conclusion was that 'weakened' myocytes are more sensitive to the monensin and digoxin treatment than normal myocytes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0931-184X
pubmed:author
pubmed:issnType
Print
pubmed:volume
49
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
329-33
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Digoxin- and monensin-induced changes of intracellular Ca2+ concentration in isolated guinea-pig ventricular myocyte.
pubmed:affiliation
Yuzuncu Yil Universitesi, Veteriner Fakultesi, Fizyoloji Anabilim Dali, Van, Turkey. imeral20@hotmail.com
pubmed:publicationType
Journal Article